title: Significance of serum immune markers in identification of global functional impairment in the oldest old: cross-sectional results from the BELFRAIL study.
abstract: The large burden and coexistence of physical disability, cognitive impairment, and depression in the oldest old makes summary markers of global functioning of great value, allowing for risk stratification. Inflammation may be a common underlying cause or represents a final common pathway. The present study investigated the association between elevated serum inflammatory markers and global functioning and its underlying aspects. A representative sample of 415 community-dwelling elderly subjects participating in the BELFRAIL study, with a mean age of 85 years, was included in the present analysis. Data on physical performance, dependence, and mental aspects of functioning and serum levels of 15 inflammatory proteins, including cytokines, chemokines, and acute-phase proteins, were assessed. Interleukin (IL)-6 was negatively associated with global functioning (odds ratio (OR) 4.35). The odds ratios for C-reactive protein (CRP) (OR 2.37) and the combined score of IL-6 and CRP (OR 2.59) were lower or not significant. IL-6 was significantly associated with physical dependence and cognitive function, and only a highly elevated serum level was associated with physical performance. Physical dependence was associated with a highly elevated CRP serum level. The proportion of functionally impaired older persons with elevated IL-6 was 81.93 %, giving a low positive predictive value (0.38), but a high negative predictive value (0.87). So, IL-6 is strongly associated with global functioning and all of the individual aspects of functioning, except suspected depression, in community-dwelling persons 80 years and older.
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven, Kapucijnenvoer 33, Blok J, 3000, Leuven, Belgium, wim.adriaensen@med.kuleuven.be.
authors.forename: Wim
authors.initials: W
authors.lastname: Adriaensen
authors.forename: Catharina
authors.initials: C
authors.lastname: Matheï
authors.forename: Gijs
authors.initials: G
authors.lastname: van Pottelbergh
authors.forename: Bert
authors.initials: B
authors.lastname: Vaes
authors.forename: Delphine
authors.initials: D
authors.lastname: Legrand
authors.forename: Pierre
authors.initials: P
authors.lastname: Wallemacq
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Degryse
mesh_terms: D000203:Activities of Daily Living; D000209:Acute-Phase Proteins / Q000276:immunology / Q000378:metabolism*; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood* / Q000276:immunology*; D001530:Belgium; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000276:immunology / Q000378:metabolism; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood* / Q000276:immunology; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000276:immunology; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D016207:Cytokines; D015850:Interleukin-6; D002097:C-Reactive Protein